Army of Poznan. Soldiers of the garrison of Poznan on a parade during one of the many patriotic manifestations.

Germany commenced direct preparations for the war with Poland in the early spring of 1939. On 3 April German generals presented to Adolf Hitler the outline directive of the Wehrmacht deployment in 1939-1940. Its second part, codenamed Fall Weiß, dealt with the plan of destroying of the Polish armed forces. That plan had to be realized by surprise attack of concentric thrusts from Silesia, Pomerania and East Prussia, beating the Polish armies concentrated in the west of the the rivers Vistula and Narew, and then pursuit eastwards to prevent the Poles to rebuild their defences along Narew, Vistula and San. The focal point of those thrusts was Warsaw, the capital of Poland and its major political, administrative and economical centre, which was supposed to be taken in the third, and last, phase of the war.

The German land forces, under the command of Gen. Walther von Brauchitsch, were organized in two Army Groups: North (Nord) and South (Süd). They concentrated for the attack on Poland 1,600,000 soldiers (and further 200,000 in the navy and air force), as well as 11,000 guns and mortars, 2,800 tanks, and 1,600 aircraft; 25 capital ships had to operate in the Baltic Sea.

The main task in the war with Poland was assigned to the Army Group South (8th, 10th and 14th Armies under Gen. Gerd von Rundstedt). Starting from Silesia, Moravia and Slovakia, the Army Group South had to unfold the offensive on Warsaw between the rivers Bzura and Wieprz, and beat the Polish forces in southern and central Poland.

Army Group North (3rd and 4th Armies under Gen. Fedor von Bock) had to establish contact between Pomerania and East Prussia, and from then strike from East Prussia to create the eastern flank of encirclement around Warsaw, and close the ring around the bulk of the Polish forces.

The 1st and 4th Air Fleets (under Gen. Albert Kesselring and Alexander Löhr) in the first phase had to attack and destroy Polish airfields, as well as Polish air force's bases and supplies. In the second phase, after grasping the command of the air, they had to strike against the deep operational rears of the Polish armies, to paralyze their mobilization, concentration, system of command, and retreat.

Air forces also had to follow advancing land forces, mainly in the sectors of operation of the armoured troops. A special attention was attached to terroristic attacks on the Polish cities, towns and villages. The lightning war did not mean merely destruction of the enemy armed forces. It was going to become a total war, aimed at overwhelming the whole nation.

The Navy Group East (Ost) under the command of Adm. Konrad Albrecht, comprised of 2 battleships, 9 destroyers and 14 submarines, with auxiliary ships, was assigned to destroying the Polish Navy in the Gulf of Danzig, securing communication lines between the Reich and East Prussia, and supporting German troops operating in coastal areas.

Auxiliary tasks in the war with Poland were assigned to subversive actions (so-called "fifth column"). Organization and realization of the subversive actions in direct connection with the military operations was assigned to the III Foreign Affairs/Defence Office (Amt Ausland/Abwehr) of the Armed Forces High Command. In the operational zone of the Army Groups North and South the direct preparation and realization of the subversive and intelligence operations was organized by the detached units of the III Office in Breslau, Stettin, Koslin and Allenstein, as well as many frontier towns. They widely used agents recruited among the German minority in Poland. The task of the subversive groups was to seize important industrial and administrative objects, prevent them from destruction by the retreating Polish troops, and hold them until the arrival of the regular German troops. The main area of the subversive actions was supposed to be the Upper Silesia - Poland's most industrialized region. There were to operate groups formed in the German part of the Upper Silesia as paramilitary squads of the Freikorps Ebbinghaus and clandestine cells of the Kampf und Sabotageorganisation. In Pomerania similar groups were formed among the members of the local Selbstschutz.

Towards the end of July subversive groups, trained in the Wehrmacht camps, were gradually assuming their positions along the Polish frontier. Later, on 15 and 16 August there came orders to start transfers of the weapons to Poland to arm German subversive groups. The Abwehr office in Stettin attached a particular importance to the operations on the communications linking the Reich and East Prussia, and seizing intact railway bridges in Grudziadz and Tczew.

The reports of the Polish intelligence kept revealing the alarming situation on the western frontier since March 1939. In July the General Staff and the General Inspectorate of the Armed Forces had no more doubts that deployment of the German divisions along the Polish border meant concentration of the Wehrmacht's bulk forces. What remained to be determined was when and where Poland would be attacked.

As soon as on 23 March 1939 Poland implemented partial, so-called alert, that is secret, mobilization, and started deploying mobilized troops along the German border stretched along 1,500 kilometres from the Augustów Forest in the north-east to the Carpathian Mountains in the south. Those were, however, only few infantry divisions and cavalry brigades, which were not able to secure adequate defence of the borders.

Economically and militarily Poland was manyfold weaker than Germany, and her strategic position did not favour defence, but favoured an invasion. In the north the area of East Prussia was looming over the vital centres of the country. Together with the "pincers" of Pomerania and Silesia it created a very convenient initial position for deep thrusts into the Polish rears. Warsaw, the capital of Poland, its political and administrative centre, and important industrial centre and a node of communications, at that time was located very close to the German borders: 270km from Silesia, 220km from Pomerania, and merely 120km from East Prussia. In case of a war Warsaw, as well as strategically and economically important areas were within the range of the enemy air forces, and in some places even long-range artillery.

The first briefing concerning the plan of the war with Germany took place at the General Staff on 4 March 1939. By the end of March there was worked out general plan of the deployment and tasks of the Polish armies and operation groups. That plan, codenamed Zachód (West), outlined in very general terms the following concept of the defensive battle:
  • to defend the areas vital for the war effort, and inflict on the Germans the heaviest losses possible,
  • to use all opportunities to counter-attack with the reserves, and prevent main forces from being defeated before the beginning of the Allied offensive in the West,
  • to undertake, upon the Allied offensive, and relieving the Polish front, offensive operations according to the overall situation.
Taking into consideration factors of the economical nature, as well as possibility of only local offensive actions in Upper Silesia, Pomerania or Danzig, the General Inspector of the Armed Forces, Marshal Edward Śmigły-Rydz decided to fight a defensive battle along the western frontiers. On 23 March 1939 the commanders of the Polish armies and operation groups received their orders:
  • Independent Operation Group Narew (Gen. Czesław Fijałkowski-Młot) had to assume defence on the north-eastern flank of the Germano-Polish border.
  • Army Modlin (Gen. Emil Przedrzymirski-Krukowicz) had to block the northern approaches to Warsaw from East Prussia.
  • Army Pomorze (Gen, Władysław Bortnowski), concentrated in the Tuchola Forest and on the River Osa, had to hold Polish Pomerania.
  • Army Poznań (Gen. Tadeusz Kutrzeba) had to hold Posnania.
  • Army Łódź (Gen, Juliusz Rómmel) was assigned to block the south-western axis of advance from Silesia to Warsaw.
  • Army Kraków (Gen. Antoni Szylling) had to defend Upper Silesia and the Carpathian Foothills.
  • Army Karpaty (Gen. Kazimierz Fabrycy) in the Carpathian Mountains had to close the passes across the border with the German puppet, the Slovak State.
The reserves had to be formed gradually after the proclamation of the general mobilization. They were supposed to build up around the Army Prusy (Gen. Biernacki-Dąb) deployed in the rears of the armies Łódź and Kraków, in a huge triangle Kielce - Radom - Tomaszow Mazowiecki; its units would reinforce armies Łódź and Kraków i the sectors where the Germans might break through their defences. Further areas of concentration of the Polish reserves were planned in the north, along the River Narew, and in the south, around Tarnow.

Yet, full mobilization could not be carried out due to mediation of the Western democracies, which tried to avoid confrontation with Hitler at any price. Eventually Poland was able to put forward about 1 million of regular troops and 300 thousand men in popular militia, 900 tanks and armoured cars, 2,000 guns, and about 400 aircraft.

Gen. Kutrzeba received his orders regarding the defence of Posnania on 23 March 1939. By then he had already completed his staff. The position of Posnania, bulging westward, did not make convenient conditions to its defenders. From there it was possible to launch offensive operations in three strategic directions: to Pomerania, to Silesia, and (hypothetically) to Berlin. An offensive on Berlin could be considered only in the categories of strategic theories. Although such concepts used to be examined at the French General Staff, Poland, till the spring of 1939, did not even undertook any serious studies of a possible war with its western neighbour. Besides, any offensive operations were ruled out due to weakness of the Polish army and Polish economy as compared to their German opponents. On the other hand, passive defence in Posnania would let the Germans a free hand to drive deep, outflanking thrusts from Pomerania or Silesia towards Warsaw, cut all its communications with the rest of the country, get to the deep rears of the Army Poznań, and eliminate it as a considerable factor in the war.

Nevertheless, despite of the military reasons against the defence of Posnania, which had to be deployed in the area deprived of natural obstacles to the advancing forces, four infantry divisions and two cavalry brigades were deployed along Poland's western border. The decision to do so was influenced by the factors of political and economical nature. Political reasons demanded that not an inch of Posnania would be surrendered to avoid creating an impression that Poland yielded to the German demands and is ready to make territorial concessions. Moreover, Posnania was a great source of food and human reserves, and its people were reputed for good soldiers; just 20 years before, in 1918-1919 they rose against the German rule and liberated their part of Poland regaining her independence.

The Polish intelligence did not detect any serious concentrations of the German troops on the other side of the border. Army Poznań faced only border guard units (Grenzschutz), incapable to engage in full-scale combat actions. So, a direct attack on Posnania was not expected, but it was necessary to close the axis Frankfurt - Poznan, and deploy reconnaissance units on the flanks to scout the enemy design.

From the onset there emerged a difference of opinions about the role of the Army Poznań in the war. Marshal Rydz insisted that the main German offensive would be driven from Frankfurt via Poznan to Warsaw, and ordered to resist that offensive. In Kutrzeba's opinion the Army Poznań had to reinforce the efforts of its neighbours: Army Łódź in the south, on the line of the rivers Warta and Widawka, and Army Pomorze in the north in Pomerania. According to this concept, Kutrzeba detached three infantry divisions and one cavalry brigade to hold the line Naklo - Kcynia - Wagrowiec - Oborniki - Poznan - Srem - Krotoszyn - Ostrow Wielkopolski. This was the first, so-called "protective", line of the Polish defence. The second, "spanning", line was prepared with the rest of the forces around Gniezno.

According to Kutrzeba's design, after exhausting all possibilities of fighting on those defence lines, the Army Poznań had to retreat, while waging impeding fights. to the main defence running from Bydgoszcz in the north, to Znin and Goplo lakes, to Uniejow the River Warta in the south. There the Polish defence was supposed to be reinforced with mobilized reserves of the Supreme Command: 2 infantry divisions from the Operation Group Kutno concentrated in the triangle Kutno - Plock - Wloclawek. In case of another development of the situation, the Operation Group Kutno could reinforce the Army Pomorze or Army Modlin on the River Drweca. Another option foresaw engaging the reserves of the Supreme Command on the junction of the Armies Poznań and Łódź, especially in case of a battle on the Warta.

Concentration of the army, realized within the framework of the general mobilization plan, was carried out as consecutive phases of the alert mobilization led to the general mobilization. They depended on the current political situation, and the estimation of the build up of the Wehrmacht forces concentrated along the Polish borders. First deployment of the units of the Army Poznań came as soon as in March 1939 within the framework of the partial alert mobilization. The 37th Infantry Regiment and some auxiliary units were brought in the vicinity of Wagrowiec. By July the whole 26th Infantry Division completed its deployment on the western border. The Podolska Cavalry Brigade, mobilized at the end of August, was assuming its positions already under the German bombs. Whereas the 14th, 17th and 25th Infantry Divisions, Wielkopolska Cavalry Brigade, popular militia brigades Poznańska and Kaliska, 7th Heavy Artillery Regiment, 3rd Air Regiment and attached squadron of armoured trains remained in their garrisons, and upon mobilization undertook fortification tasks. The headquarters of the Army Poznań were prepared in Gniezno where General Kutrzeba arrived with his staff at night from 28 to 29 August from Poznan.

Beginning of the first days of the alert mobilization, garrisons throughout the Posnania remained in the state of permanent combat readiness. Being alternately engaged in service duties, training or fortification works, they were ready to engage the invading enemy. As mobilization proceeded, the units of the Army Poznań concentrated according to Kutrzeba's plan as follows: the 26th Infantry Division (Col. Adam Ajdukiewicz-Brzechwa) assumed defences around Wagrowiec; the 14th Infantry Division (Gen. Franciszek Wład) covered Poznan - the main administrative, industrial and communication centre; Wielkopolska Cavalry Brigade (Gen. Roman Abraham) deployed along the middle Warta, with the main points of defence around Smigiel, Leszno and Rawicz; the 25th Infantry Division (Gen. Franciszek Alter) - on the River Prosna along the line Krotoszyn - Ostrow Wielkopolski - Kalisz.

Fortification began on the turn of March and April, at once on limited scale due to the lack of precise directives from the Supreme Command, and necessity to spare crops. Directives and plans from the Supreme Command came in June, and fortification intensified, especially in the areas of Znin, Kolo, Wagrowiec, Poznan and Kalisz.

Defence preparations and growing political tensions in the Germano-Polish relations revealed another problem. Anti-Polish among the local Germans was growing. Young men of German nationality used to dodge the conscription and defect to Germany, where they volunteered for the Wehrmacht or subversive "fifth column". Inside Poland they made a sophisticated network of German agents, gathering arms, providing valuable intelligence data, and maintaining proscription lists of the Poles intended to be eliminated, especially the veterans of the 1918-1919 uprising. Smartly concealed radio-transmitters reported movements of the Polish military units.

Meanwhile there were passing the last days of August 1939, full of apparent everyday's routine, under which were concealed unrest, tension and dread. Just like in the whole country, also in Posnania people were recruited to dig trenches, anti-tank ditches and air-raid trench shelters. In Poznan they dug 25km of trenches; in Leszno - 6km and in Inowroclaw - 14km. The action of canvassing donations on the state defence - Anti-Air Defence Fund (POP), Naval Defence Fund (FOM), National Defence Fund (FON) - brought more than 30 million złotys.

Very popular were paramilitary and social aid organizations - Anti-Air Defence (OPL), Polish Red Cross (PCK), Military Training (PW), Women's Military Training (PWK), Polish Western Union (PZZ), Rural Armed Emergency (PZW), Federation of the Polish Unions of Homeland Defenders' (FPZOO) and others. The Social Information Network (SSI) recruited volunteers to carry out special tasks, intelligence and sabotage, in the rears of the invading armies. On 23 August, by Kutrzeba's order, SSI cells started collecting arms and explosives in secret hide-outs, where they had to await the hostilities.

Beginning of 24 August permanent combat alert was in effect in all garrisons, and mobilized reservists called to arms started gathering in the barracks. General mobilization, announced few days later, completed the preparations for the combat operations. On 29 and 30 August arrived orders to deploy the troops on the combat positions and be prepared to repel an enemy attack.

Regiments 10th and 37th from the 26th Infantry Division assumed positions in the west of Golancza and Wagrowiec; their northern wing was covered by a battalion detached from the 18th Infantry Regiment. The rest of the 18th Rgt., and Popular Militia Battalion Żnin were kept in reserve and assigned to cover the division's headquarters at Wapno Nowe.

In the western approaches of Poznan the 14th Infantry Division deployed the Poznańska Popular Militia Brigade in the first line, and the 57th Infantry Regiment in the second line; cavalry units were assigned to cover their southern wing. The 7th Mounted Rifles Regiment from the Wielkopolska Cavalry Brigade was deployed between Poznan and Oborniki. Reserve cavalry units were deployed in Swarzedz, and the 58th Regiment was covering the division's headquarters in Murowana Goslina.

Detached Units Czempiń, Leszno and Rawicz, composed of the units of the 17th Lancers Regiment and 55th Infantry Regiment were assigned to hold positions along the state border, while along the River Warta were deployed Popular Militia Battalions Rawicz, Kościan, Leszno, Jarocin and one battalion from the 68th Infantry Regiment of the 17th Infantry Division. They were under the command of the headquarters of the Wielkopolska Cavalry Brigade in Srem. Reserves - 55th Infantry Regiment, one reserve battalion, and 15th Lancers Regiment - were concentrated at Zaniemysl.

The 25th Infantry Division assigned two of its infantry regiments to hold the line of the River Prosna, 56th at Krotoszyn and 60th at Ostrow Wielkopolski. while in the second line there were deployed the 70th Infantry Regiment from the 17th Infantry Division near Stawiszyn, and the 29th Regiment near Kalisz, where the division had its headquarters.

The rest of the 17th Division was concentrated in the reserve near Wrzesnia and Gniezno, where was also the division's headquarters, while the Podolska Cavalry Brigade was arriving by the railways and concentrating near Nekla.